Longer Course of Imatinib Better in Trial for GI Stromal Tumor

(HealthDay News) – A longer course of imatinib (36 months vs. 12 months) significantly improves recurrence-free survival (RFS) and overall survival in postoperative patients at high risk for recurrence of gastrointestinal stromal tumor (GIST), according to a study published in the March 28 issue of the Journal of the American Medical Association.

Heikki Joensuu, MD, of Helsinki University, and colleagues conducted a randomized, open-label phase 3 study in 24 hospitals in Finland, Germany, Norway, and Sweden. Patients were given imatinib (400mg per day) orally for either 12 or 36 months; treatment was initiated within 12 weeks of surgery. The risk of GIST recurrence was estimated using the modified National Institutes of Health Consensus Criteria.

Over the median follow-up of 54 months, the researchers found that patients assigned to 36 months of imatinib had significantly longer RFS compared with those assigned to 12 months (hazard ratio [HR], 0.46; five-year RFS, 65.6% vs. 47.9%) and longer overall survival (HR, 0.45; five-year survival, 92% vs. 81.7%). Imatinib was generally well tolerated, but 12.6% of patients assigned to the 12-month group and 25.8% of patients assigned to the 36-month group discontinued imatinib for a reason other than GIST recurrence.

"Compared with 12 months of adjuvant imatinib, 36 months of imatinib improved RFS and overall survival of GIST patients with a high risk of GIST recurrence," the authors write.

Several authors disclosed financial ties to pharmaceutical companies, including Novartis, which partially funded the study.